[PATCH AUTOSEL 4.9 31/48] RDMA/core: Do not expose unsupported counters

From: Parav Pandit [ Upstream commit 0f6ef65d1c6ec8deb5d0f11f86631ec4cfe8f22e ] If the provider driver (such as rdma_rxe) doesn't support pma counters, avoid exposing its directory similar to optional hw_counters directory. If core fails to read the PMA counter, return an error so that user can

[PATCH AUTOSEL 4.9 31/48] RDMA/core: Do not expose unsupported counters

From: Parav Pandit [ Upstream commit 0f6ef65d1c6ec8deb5d0f11f86631ec4cfe8f22e ] If the provider driver (such as rdma_rxe) doesn't support pma counters, avoid exposing its directory similar to optional hw_counters directory. If core fails to read the PMA counter, return an error so that user can